Method of and apparatus for concentrating ores



' June 12, 1923.

. 1,458,467 s. H. DOLBEAR METHOD OF AND APPARATUS FOR CONCENTRATING ORES Filed Nov. 4, 1919 2 Sheets-Sheet 1 Egg Z IN V ENTOR June 12, 1923. 1,458,467

S. H. DOLBEAR METHOD OF AND APPARATUS FOR CONCENTRATING ORE'S Filed Nov. 4 191: 2 Sheets-Sheet 2 INVESTOR Patented June 1 2, 1 923.

E TATES PATNT OFFICE.

SAMUEL H. DOLBEAR, OF SAN FRANCISCO, CALIFORNIA, ASSIGNOR OF ONE-HALF. TO

EDWIN LETTS OLIVER, OF SAN FRANCISCO, CALIFORNIA.

METHOD OF AND APPARATUS FOR CONCENTRATING ORE-S.

Application filed November 4, 1919. Serial No. 335,664.

To all whom it may concern Be it known that SAMUEL H. DOLBEAR, a citizen of the United States, residing at San Francisco, in the county of San Francisco and State of California, has invented new and useful Improvements in Methods of and Apparatus for Concentrating Ores, of which the following is a specification.

This invention relates to a method of and apparatus for concentrating ores, and particularly pertains to a process involving the utilization of the well-known preference of certain substances called selective reagents for metallic and some metalliferous and other substances over gangue.

The object of this invention is .to effect economically the concentration and separation of the valuable mineral or metalliferous content of ore, or other materials, from the gangue Or other portions that it is desired to reject.

I have discovered that if an ore or other substance containing mineral particles which exhibit a preferential afiinity or wetting by the selective reagents is mixed with a suitable selective reagent in a. medium of suitable liquid, and then brought into contact With a surface or body of metal or a metalliferous substance or any solid surface exhibitinga similar affinity for the so-called selective reagents, the mineral particles pres-. ent in the pulp adhere to such metallic surface while the waste or gangue exhibits no such phenomena. A concentration is thereby effected and the metalliferous concentrate may then be removed from the sheet of metal and saved.

Briefly, the invention comprehends reducing the ore to the desired degree of fineness, mixing this with water and a small amount of selective reagent, such as oil, circulating.

this pulp mixture about metallic surfaces, and taking advantage of the factthatthere is found to be coherence between such metallic particles and the metallic surface or surfaces.

The accompanying drawings represent one form of an apparatus suitable for practicing the invention:

Fig. 1 being a longitudinal sectional view of same;

' Figs. 2 and 3 being cross sections taken on the lines 2-2 and 3-3 respectively of Fig. 2.

In the drawings I show a drum 10, the inner surface of which is constructed of metalselective reagent is moving. a

lie, metalliferous or other solid substance for which a selective reagent exhibits a, preferential affinity, and in the following specification I have used the term collecting element to designate a surface of this nature. The drum is mounted to revolve on rollers 11 with which tracks 12 on the periphery of the drum engage. The drum is driven at the desired speed by means of a belt passing around a channel ring 13 on the periphery of the drum, and pulp containing a selective reagent such as oil is fed to the interior of the drum through a feed spout 14, and the oil may or may not be mixed with the pulp prior to introducing it into the drum. The

pulp-is usually treated with a suitable selecwithin the drum. The feed end of the pulp is preferably formed with end flanges 15 to retain the pulp within. Also this end of the drum may be fitted interiorly with bafiieplates 16 by means of which a. mixing of the pulp and oil is accomplished in cases where the mixing is not done outside of the drum. The drum is open at its end opposite the feed end and is preferably tilted down- 35 wardly towards the discharge end, whereby the pulp will graduall and slowly work its way through the lengt of the drum and in so doing will be brought into contact with the inside surface of the drum throughout the circumference of the latter, on, account of the rotation of the drum. The oil or other selective-'reagentsexhibits a preferential affinity for metallic and metalliferous substances and consequently the mineral par-- ticles contained in the pulp will become coated with oil and will, therefore adhere to the drum through which pulp treated with a The mineral particles are removed from the surface of the drum by means of a wiper 16 ivoted on a. longitudinal support '17 an pressed against the surface of the drum by means of a counterweight 18. A trough 19 extends longitudinally through the drum and is arranged in position to receive the mineral particles from the wiper. A worm or screw 20 is fitted within the trough 19 and driven by means of a pulley'2'1 to convey the mineralparticles to one end of the trough where a receptacle 21 receives them. A sluice or I launder 22 is arranged at the discharge end of the drum to receive the gangue, or waste.

It will be understood that the kind of material used in the construction of the drum or collecting element, the rate of movement of said collecting element, and the character and percentage of selective reagent used in the pulp should be determined by preliminary tests, since they vary with the nature of the ore being treated. Forexample, with a drum having a lining of tin and rotated at a speed of 16 R. P. M. into which is introduced Galena ore from the Joplin district, Missouri, containing 10% galena and 90% insoluble and ground to pass a forty mesh screen, and which ore had been treated. with one-half of 1% of #100 flotation oil of the Pensacola Tar & Turpentine Co. gave a concentrate adherin to the drum which contained 39% ga ena, and tails containing lessthan 1% galena, the extraction being 92.36%. The same drum operating at a speed of 12 R. P. M. on an ore from the Joplin district, Missouri, containing 10% sphaleriteand 90% insolubles, ground to pass a forty mesh screen and treated with onehalf of 1% flotation oil of the character above mentioned resulted in a concentrate containing 48.37% sphalerite and tails containing about 1% sphalerite, the extraction being 91.9%. In both tests'mentioned in the foregoing the drum was allowed to revolve under the charge for 11} minutes.

With a drum having an inner surface of zinc and rotated at 30 R. P. M., a charge of sphalerite ore from the Joplin district, Missouri, containing 10% of sphalerite and 90% insolubles and ground to pass a forty mesh screen, said ore being treated :with one-half of 1% of #609 flotation oil of the Barrett Company of New York, the results showed a concentrate containing 35%sphalerite and tails containing 2% sphalerite, with an extraction of 84.72%. I

This process possesses advantages over what is known as the flotation process, some of which advantages are as follows:

The concentrate recovered by this process is substantially dry and does not require the use of thickening or dewatering devices.

No problems of maintaining a froth-constant are involved.

The ore to be treated need be crushed to only that fineness necessary to free mineral particles from the gangue. it has been found by experiment that ores crushed to pass a forty mesh screen may be concentrated by this method and in some cases a much coarser product has been used with success. In flotation it is generally necessary to pulverize the ore to 150 mesh or finer.

A further advantage lies in the ability of In most cases the following claims designates the mineral,

metallic or me'talliferous content of substances, which content is recoverable by treatment under this process.

By the term selective reagent in the claims is meant oil or any non-metal.

substance that exerts a selective action on metallic substances such as oil exerts.

The term relatively free from selective reagent, as herein used, refers to the amount of oil present on the surface upon which the'oil-particles are retained as compared to the amounts of oil present on surfaces such as are employed in carrying out the invention disclosed in United States Patent No. 899,149 of J. D. Wolf and, also, in other similar processes in which oil or other selective reagent is spread upon the surface of a belt or similar instrumentality. As hereinabove set forth, the process herein disclosed contemplates the employement of only sufiicient oil to coat the mineral particles and cause them to adhere to a surface exhibiting a preference for oil or other selective reagent. I am familiar with the amalgamation of gold and other metals by the use of quicksilver; hence, I disclaim quicksilver as a type of selective reagent to be utilized in practicing my invention.

Having thus described my invention, what I claim and desire to secure by Letters Patent is:

1. A method of separating from gangue or waste those mineral particles which exhibit a preferential wetting by selective reagents, consisting of treating a suitable pulp containing such mineral particles with a selective reagent, bringing the pulp so treated into contact with a solid collecting eement which exhibits a preference for selective reagents, and maintaining the portion of the element presented to the pulp relatively free from the selective reagent.

2. A method of concentrating ore by employing the preference of a selective reagent for mineral articles to cause such articles in a finely divided state to adhere to a solid element in and of itself exhibiting a preference for such selective reagent, and maintaining a portion of the solid'element relatively free from the selective reagent.

3. A method of separating from gangue or waste those mineral particles which e'xhibit mechanically manager a preferential wetting by selective reagents, consisting of treating a suitable pul containing such mineral particles with selective reagents, bringing the pulp so treated into contact with the surface of a metal also exhibiting a preference for selective reagents, thereby causing the mineral particles to adhere thereto, and maintaining the portion of the element presented to the pulp relativey free from the selective reagent.

4. A method of separating from gangue or waste those mineral particles which exhibit a preferential wetting by selective reagents, consisting of treating a suitable pu p containing such mineral particles with a selective reagent, bringing the pulp treated into contact with the surface of a metal-collecting element, removing from such collecting ele 'ment the mineral particles adhering thereto,

and maintaining the portion of the collecting element presented to the pulp relative y free from the selective reagent.-

5. A method of separating from gangue or waste those mineral particles which -exhibit a preferential affinity for selective reagents, consisting of treating a suitable pulp containing such mineral particles with a selective reagent, bring the pulp so treated into contact with a moving metallic collecting element which in and of itself exhibits a preference for the selective reagents, and maintaining the ortion of the element presented to the pn p relatively free from the selective reagent.

'6."A method of separating fromgangue or waste those mineral particles WhlOll exhibit a preferential wetting by selective reagents, consisting of treating a suitable pulp containing such mineral particles with 'a selective reagent, bringing the pulp so treated into contact with a metallic collecting element having a rotary movement and which in and of itself exhibits a preference for the selective reagents, and maintamlngthe surface of the element relatively free from the reagent.

7. A method of separating from angu or waste those mineral particles which exhibit a preferential wettmg by selective reagents, consisting of treating a suitable pulp containing such mineral particles with a selective reagent, bringing the pulp so treated into contact with the meta lic. surface of a revolving drum and which surface. in and of itself exhibits a preference for selective reagents, and maintaining said surface relatively free from the reagent.

8. A method of separating from gangue or waste those mineral particles which ex hibit a preferential wetting by selective reagents, consisting of treating a suitabe pulp containing such mineral particles with a selective reagent, bringing the pulp so treated into contact with an inner metallic surface of a revolving drum exhibiting, in and of itself, a preference for selective reagents, an maintaining such surface relatively free from the reagent.

9. An apparatus for separating mineral particles from gangue, comprising a metallic surface, exhibiting a preferential affinlty for selective reagents, with which pulp containing mineral particles is brought into contact, means for maintaining the portion of the contacting surface to which pulp is presented relatively free from the selective reagent and means for removing the mineral particles adhering to such metallic surface. V 10. An apparatus for separating mineral particles from gangue, comprising a revolving metallic surface which exhibits a preference for selective reagents, with which pulp containing mineral particles also preferentially wetted by a selective reagent is brought into contact, means for maintainingthe portion of the contacting surface to which pulp is presented relatively free from the selective reagent and means for gemoving particles adhering to such surace.

11. An apparatus for separating mineral particles from gan e, comprising a surface of a solid ex ibiting a preferential.

afiinity for selective reagents, means for 'bringlng pulp treated with a selective reselective reag nt into the interior of said drum, and maintaining the portion of said inner surface to which pulp is presented relatively free from the selective reagent, and means-for removing the mineral particles adhering to the surface of said drum.

13. An apparatus for separating mineral particles from gangue, comprising a revolv- 1n drum hav1n an inner surface which exhibits a pre erence for selective reagents, means "for introducing pulp containing mineral particles, treated with a selective reagent, at one end of the drum, said drum being arranged to continuously discharge the gangue at the opposite end, and means-for malntaining its interior surfaces relatively free from the selective reagent, and means for removing the mineral particles adhering to the surface of said drum.

14. An apparatus for separating mineral particles from gangue, comprising a revolving drum, means for introducing pulp conteining mineral particles to the interior of said drum, means for treating the Pulp With aselective reagent, seid drum having an inside surface exhihiting s preference for selective reagent, and means for keeping the inside surface of the drum substantially free from the selective tea-gent.

1 15. A method of separating from gengue or Waste those mineral osrticles which exhibit a preferential Wetting by selective reagents, consisting in treating the Waste with an oleaginons selective reagent in uantity sutiicient to cost the mineral particles with e film, end bringing the mineral particles so treated into contact with a collecting element which is free "from the selective reagent used.

16. A method of separating from gangue or Waste those mineral articles whlch exhibit e preferential Wetting by selective reagents, consisting in treating the Waste with an oleaginous selective reagent in quantity suficient to coat the mineral parmesses ticles with at film, end bringing the mineral particles so treated into Contact with a collecting element which is free from the selective reagent usecl but which has an afiinity for the selective reagent nsecl.

l7, A method of separating from gengue 01' Waste those mineral articles which exiii-hit e preferential Wetting by selective reagents consisting in treating the Waste with en oleegincus selective reagent in quantity not greater then 2% relative to the Weight 01? the ore treated to cost the mineral particles with e film, and hiring the mineral particles so treeteol into contact With a collecting element which is tree from the selective reagent used.

In testimony whereof l have hereunto setmy hand in the presence of two subscribing Witnesses.

' SAMUEL H, DULBEAR. \/Vitnesses2' R. B. AWES, Ni Enti es. 

